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STRTOL(3)                  Library Functions Manual                  STRTOL(3)

       strtol, atol, atoi - convert string to integer

       long strtol(str, ptr, base)
       char *str, **ptr;
       int base;

       long atol(str)
       char *str;

       int atoi(str)
       char *str;

       strtol() returns as a long integer the value represented by the charac-
       ter string pointed to by str.  The string is scanned up  to  the  first
       character  inconsistent with the base.  Leading ``white-space'' charac-
       ters (as defined by isspace() in ctype(3V)) are ignored.

       If the value of ptr is not (char **)NULL, a pointer  to  the  character
       terminating the scan is returned in the location pointed to by ptr.  If
       no integer can be formed, that location is set  to  str,  and  zero  is

       If  base  is positive (and not greater than 36), it is used as the base
       for conversion.  After an optional  leading  sign,  leading  zeros  are
       ignored, and ``0x'' or ``0X'' is ignored if base is 16.

       If base is zero, the string itself determines the base thusly: after an
       optional leading sign a leading zero indicates octal conversion, and  a
       leading  ``0x''  or  ``0X'' hexadecimal conversion.  Otherwise, decimal
       conversion is used.

       Truncation from long to int can, of course, take place upon  assignment
       or by an explicit cast.

       atol(str) is equivalent to strtol(str, (char **)NULL, 10).

       atoi(str) is equivalent to (int) strtol(str, (char **)NULL, 10).

       ctype(3V), scanf(3V), strtod(3)

       Overflow conditions are ignored.

                                6 October 1987                       STRTOL(3)